Fuel system for starting



. E. 0. WIRTH ETAL 2,450,175

FUEL SYSTEM FOR STARTING Sept. 28, 1948.

Filed Sept. 4, 1945 2 Sheets-Sheet 1 Sept. 28, E. o. WIRTH ETAL- muSYSTBII run sun-rim Filed Sept. 4, 1945 2 sneet s sneat 2 210- if [06 E;.202 26% l 2a; 1 1]] N JIM, 1 4 Jami 54 Patented Sept. 28, 1948 Emil O.Wirth, South Bend, Ind., and William B. Leiblng, Detroit, Mich.; saidWirth assignor to Bendix Aviation Corporation, South Bend, hit, acorporation of Delaware; said Leibing alsignor to Leibing-FageolCompany, Detroit,

Mich.

Application September 4, 1945, Serial No. 814,156

29 Claims. (Cl. 123-180) This invention'relates generally to fuelsystems for internal combustion engines, and more particularly to meansfor supplying an auxiliary or supplemental quantity of fuel to meet theengine requirement under certain abnormal conditions of operation.

The present invention is shown as being used in connection with thefuel'system disclosed in the application of Leibing and Fageol, SerialNo.

533,848, filed May 3, 1944. While very valuable when applied to thistype of fuel system, which will be hereinafter more particularlydescribed, it is not limited to such use but is obviously available,with or without modification, in a great variety of cases where asupplemental quantity of fuel is desired.

As is well known, an internal combustion engine requires a richer fuelmixture for starting when the engine is cold than for operation atnormal temperatures. In present day carburetors, enrichment for startingis generally effected by cutting down the quantity of air. for the fuelmixture as'by closing the choke valve of the carburetor. This method ofsecuring mixture enrichment for starting a cold engine impairs thevolumetric eiliciency and makes cold starting more difilcult. A moresatisfactory method of securing such enrichment is accomplished byproviding an additional or auxiliary quantity of fuel whereby asubstantially unrestricted supply of enriched mixture may be secured. Itis therefore, an object of the present invention to eil'ect enrichmentfor such cold starting by the latter method.

Another object of the invention is to provide means to facilitatestarting of the engine which will be automatic in its operation.

Another object of the invention is to provide a generally new andimproved fuel system for automatically controlling the fuel to air ratiounder cold starting and warming up conditions of appended claims.

In the drawings:

Figure 1 is a diagrammatic view of a fuel system embodying the presentinvention;

Figure 2 is an enlarged diagrammatic sectional view of the primingdevice;

Figure 3 is a sectional view of a temperature responsive fuel controlwhich is adapted to vary the quantity of auxiliary fuel delivered to thecarburetor; and

- Figure 4 is a diagrammatic viewof a deiiooding arrangement which maybe used in the present system.-

The fuel system generally The fuel system illustrated in the drawingscomprises the usual fuel tank It, connected by a conduit H to a fuelpump it, of standard or known construction. The pump may be of thediaphragm type commonly used on present day automobiles, but forsimplicity is shown as a centrifugal pump having a by-pass i6 leadintfrom its outlet side back to the conduit l2 andv controlled by apressure responsive valve It. Whatever the. type of pump, it shouldsupply fuel to the carburetor at a fairly constant pressure, and shouldpreferably prevent flow through the line when the engine is notoperating. Fuel pumps commonly used on automobiles and which supply fuelat a pressure of about five pounds per square inch, with variations ofabout 10 per cent the invenplus or minus with varying engine speeds, aresatisfactory for the purposes of this invention.

An outlet line 20 leads from the pump to a separating chamber 22, fromthe upper portion of which a return line, comprising conduits 2t and 28,conveys excess fuel, together with any vapor which may be present in theline, back to the tank Ill. The conduit 24 may be provided, at its pointof connection with the chamber 22, with a restriction 21 of such size asto permit pressure to be built up in the chamber. At the outlet ofchamber 22 is a filter, preferably of theknown type formed of acylindrical pile of disks 28 wherein the fuel flows radially inwardlythrough apertures at the edge of the disks to an axial outlet passageand thence, in the illustrated embodiment, to passage 30. From thepassage so the fuel passes into a chamber 32 in which a valve 34 isdisposed and urged in the closing direction by a spring I. The valvecontrols the flow of fuel to a fuel discharge nozzle II which dischargesinto the induction passage of a carburetor. It is provided with-a stemlll which is adapted to be engaged by one end of a lever 42 pivoted atit and actuated by a cam 45 and a vane 41 disposed in the carburetorinduction passage It and adapted to be actuated by air flow through saidPWWB Vane ll which is pivoted on an oil- In the present arrangement, thevalve ward cam 12.

aasal'rs center shaft anterior to the throttle valve is rotated in aclockwise direction by air flow in the inductio passage, and, as aresult, cam 45 which is carried by said vane and the lever 42 are movedin the direction to open fuel valve 34 to discharge fuel through nozzleit into the induction passage.

A primer. more fully described hereinafter but indicated generally at I,is interposed in the return line between the conduits 24 and 20. thefuel entering said primer by way of the conduit 24 and normally leavingsame by way of conduit 2|.

Electrical control for the primer The primer is provided with asolenoid, indicated generally at ll in Figure '2, and more particularlydescribed hereinafter, which is connected with the primary circuit ofthe engine ignition system. Genera-11y such ignition systems include astorage battery ll grounded at I! and having a wire 8! leading to theignition switch, generally indicated at II, and having a movable switchmember II adapted to engage a fixed switch contact II. From the contactll a wire I2 leads to a spark coil 84 which is connected by a wire itwith a terminal Cl secured in casing IO of the distributor. Withinthedistributor is an interrupter cam 12 secured to a drive shaft 14. Thecam may have any number of high spots or projections. depending on thenumber of cylinders of the engine, but in the present instance six areshown, the device being used in connection with a six-cylinder engine.The cam is adapted to contact amovable arm or lever II which is pivotedat II and is provided with a cam contact point-ll of fiber or otherinsulating material. The free end of the lever 18 1 carries a contactpoint 82 which is adapted to contacta fixed contact point 84 secured toan adjustable plate II which is connected with the ground II by a wire9|. The lever II is connected by a spring 1! with the terminal ll, saidspring urging the lever counterclockwise or to- A wire 92 is connectedto the terminal 88 of the primary circuit and leads to a bi-metallicthermostatic element I which may be housed in a hot spot 80 of theengine exhaust nozzle :0. However, an independent auxiliary fueldischarge nozzle may be used if desired. When the primer is inoperativethe fuel in chamber I i4 is adapted to flow through passages III and I2.and thence into the conduit II which carries said fuel back to the tankll.

Passage III is controlled by a valve Ill secured to the one free end ofa lever III, which lever is pivoted at I intermediate the lever's ends,and a spring I", of proper calibration, is adapted to urge the oppositeend of lever III in a clockwise direction for urging the valve IIIclosed. The lever I32 and valve I" are of suitable magnetic materialsuch as iron and the pivot pin I is preferably of brass or othersuitable non-magnetic material. The spring I" should also be ofnon-magnetic material or, if it is of a magnetic materiaL. it should beinsulated either fromthe lever I" by a washer or the like, or insulatedfrom the main body section I" against which it is adapted to react.

The valve I is adapted to be actuated by the solenoid I. which has aniron core Ill through which the passage I28 extends. The solenoid orcoil I" is wound about the iron core I", said coil being disposed in thehousing Ill formed by a portion of the upper section III. At the ends ofthe coil 0 are fiber washers H2 and I re iii manifold 98. Althoughthethermostat is shown mined value which is approximately normal engineoperating temperature. The contact point II. is connected to thesolenoid ll by a wire I" and said solenoid is also connected with thecontact point Ill of the ignition switch by a wire Primer The primer,comprises a main body section I", a lower section ill, and an uppersection III. Fuel from the conduit 24 enters the passage 2 in the uppersection III and thence flows into a chamber Ill formed in the lowerportion, as shown in the drawing, of the upper section. Priming fuelfrom the chamber lil is-adapted to flow through a passage Ill and a Jetll'l secured in an enlarged portion of said passage 0. The fuel then isadapted to enter a chamber I" in the lower portion of the main sectionllt'and thence flow through a passage I22 .and enter a conduit I whichis connected with flit ill?! spectively, the latter being at the upperend of said coil. These washers are press fitted onto the core I".Adjacent the lower end of the coil is a brass plate I48 which is alsopress fitted onto the core in and secured thereon by overturning an endportion I50 of said core. The plate I" is alsopress flttedinto a recessof the section II. adjacent the chamber I and aneoprene gasket III isinterposed between said plate Ill and the bottom of the recess. The coilis encased in an iron housing I" closed at its upper end I" and open atits lower end. The lower end of the housing Ill sealabiy receives thefiber washer I42 and a fiber washer III is sealabiy received in anopening provided therefor at the end ill of the iron housing and is alsoin scalable engagement with a shoulder and reduced end portion of thecore III, there being a central opening in said washer III which is inregister with the passage I28. The wires I02 and ill extend through thehousing I in insulating conduits I" which are snugly fitted intoopenings provided therefor in the housing ill, the housing ill andwasher l. The purpose of the foregoing construction, relative to thesolenoid is to adequately seal the coil against the entrance of fuel andalso to provide for relatively powerful' magnetic impulses for actuationof the valve in. It is to be noted that the valve I3! is tapereddownwardly and cooperates with the entrance of the passage III forcontrolling said passage. The upper end of valve I30 is somewhat convexat I62 and this portion III is adapted to cooperate with the adjacentend of the passage I26 which is in substantial alignment with thepassage ill.

The Jet m is controlled by a valve its having a stem I58 whichis-connected with a diaphragm I88 which forms one wall of the chamberIn. The diaphragm is marginally clamped between the'main section I" andthe lower section III- which contains a chamber I10 therein opposite thechamber I20. The stemi6! is shown as being formed integrally with aspring retainer I12 on the side of the diaphragm opposite the valvealthough it may be a separate piece secured to said retainer. On thevalve side of the diaphragm I admin a washer I14 is provided in clampingassociation with the diaphragm and is held in position by an overturnedportion I10 of the retainer I12. A spring I" is disposed in the chamberI I and reacts between the spring retainer I12 and a spring retainer I00of an adjustment screw I02 which is threadably received in an opening inthe lower wall I04 of the lower section I00. A look nutIOl is receivedon the screw I02 for securing same in adjusted position. The chamber I10has a passage I00 which is connected witha conduit I 00 leading to theengine intake manifold I02 thus the chamber and consequently thediaphrgam I00 are subjected to manifold vacuum (posterior to thethrottle valve) or engine charging pressure. It is to be noted thatthe.valve I04 is of the reverse type and that the spring I10 urges saidvalve in the opening direction while the manifold vacuum urges the valvein the closing direction.

Operation Assuming the engine is to be cranked when cold, the free endof thermostat 04 will be in contact with the point I00 to provide anelectrical connection between the wire 02 and the wire I02. The valveI04 will be urged to relatively wide open position by spring I18 and thevalve I30 will be urged to the closed position by the spring I00.

To start the engine the ignition switch 00 is closed as well as thestarter switch not shown. The starter motor will begin to'crank theengine and as the pistons start to reciprocate they will pump the normalfuel mixture into the cylinders and effect such movement of the vane 41in the induction passage which actuates lever 42 as to effect opening ofthe fuel valve 34. Simultane ously the pump I4 will supply fuel throughconduit 20, chamber 22, filter 20, conduit 30, chamber 32 and fuelnozzle 30. With the valve I30, Figure 2, in the position shown excessfuel would be carried by the return line 24, through conduit II2,chamber II4, passage I00 and conduits I28 and 20 and delivered to thefuel tank I0. However, as the engine is cranked, the distributorinterrupter cam 12 will be rotated, by shaft 14, and effect a making andbreaking of the contact points 02 and 04. 'Each time there is a makingof said contact points there will be an electrical impulse to thesolenoid which will become energized and effect a counterclockwisemovement of the lever I02, thusopening the valve I00 and closing theadjacent end of the conduit I20.

Excess fuel is then diverted from the return conduit 20 into the passage"0, orifice IIO, chamber I20, passage I22 and thence into the conduitI24 which carries said fuel to the fuel nozzle 00, posterior to valve34, from which it is discharged into the induction passage. Thus anauxiliary or supplemental supply of fuel is delivered to the inductionpassage to enrich the fuel mixture delivered to the engine. The quantityof the sup plemental fuel delivered to the engine is varied inaccordance with manifold vacuum or engine charging pressure to which thediaphragm I00 is subjected, said vacuum being adapted to draw saiddiaphragm downwardly, as shown, and effect restricting movement of thevalve I04.

As the cam I2 rotates directly in accordance with engine speed it willbe obvious that as the speed of the engine increases, as when the enginebegins to fire or is accelerated the more frequently will be theelectrical impulses to the sole-' noid and consequently the valve I00will be 6 I opened with greater frequency, corresponding to theincreased speed of the engine. The auxiliary fuel will continue to besupplied to the engine as long as the temperature of the engine is belowa predetermined value but when said temperature exceeds said value thefree end of the bi-metailic thermostat 04 will move in a direction tobreak theconnection between wires 02 and I02, whereupon the valve I30will be closed by spring I20 and retained in said position and thepassage I20 will be opened and will remain open. Overflow of fuel willthen be carried back to the fuel supply tank "by conduit 20 as long asthe engine is operating at'normal temperatures.

During the warming up period of the engine, when the thermostat switch04 is closed, the valve I04 will control the metering orifice of the JetIII in accordance with manifold vacuum.

When the manifold vacuum is high the valve will be more nearly closedthan when the vacuum is low. Thus should the throttle valve be opened,as for acceleration of the engine, a greater supply of auxiliary fuelwill be provided than when the engine is idling. This is a desirablefeature in securing proper acceleration of the cold engine.

It is to be noted that the possibility of flooding the engine cylinderswith excessive quantities of fuel, such as would prevent the engine fromstarting, is minimized by arranging the solenoid circuit in such a waythat when the ignition switch is open the solenoid circuit is also openand no auxiliary fuel will be supplied to the engine. Consequently onlythe normal quantity of fuel will be supplied and in most cases floodingwill not occur.

It is also desirable to control the quantity of auxiliary fuel deliveredto the engine in accordance with engine temperature conditions. Forexample, when the engine is started cold a greater ratio of fuel for thefuel mixture is generally required than when the engine is warmed up andit is desired to supply the auxiliary fuel in such a manner as toprogressively decrease the quantity thereof as the engine warms up.

In the present invention such control of the auxiliary fuel is providedby a thermostatic device which, as shown, comprises a. bi-metallicthermostat element 220, Figure 3, having a substantially U-shaped formlocatedin the chamher. The thermostat is positioned horizontally, asshown in the drawing, and the lower arm is attached to the upper face ofthe main section I00 by screws 222. The other arm, 224, extends over theadjacent free end of lever I32. When the thermostat is'cold the armsthereof separate to a position whereat movement of the lever I02 isunrestricted by the thermostat so that the maximum quantity of auxiliaryfuel is supplied to the engine when the primer is operating. As thethermostat warms up the upper arm 224 moves downwardly and limitsopeningmovement of the valve I30 in accordance with the temperature ofthe fuel which reflects engine temperature. When the engine has fullywarmed up the fuel in chamber II4 reaches a temperature of such value asto cause the thermostat 220 to retain the valve securely in a fullyclosed position. At this time, of course, the thermostatic switch 04opens so that a solenoid is rendered inoperative.

However, if desired, as an additional precaution, means for effectingdeflooding of the engine may be provided, such an arrangement being 7 sshown in Figure 4. In this figure there is shown a throttle body I"having athrottle 202 located therein and mounted on a throttle shaft 2to which is attached the usual throttle lever Ill which is adapted to beconnected by suitable linkage with the accelerator pedal. not shown. InFigure l throttle body 200 is shown mounted an intake manifold I02. Thethrottle lever. it is provided with an extension 208 having a laterallyturned portion III! which is adapted to be moved to a position to engageand open a normally closed switch, indicated generally at 212, which isinterposed in the solenoid circuit. The switch is so located that itwill be openedupon movement of the throttle in the opening directionbeyond a predetermined position. .When the engine is cold. the primerwould ordinarily supply auxiliary fuel, when the switch is closed. inthe manner above described but when said switch is open the primer willbe rendered inoperative and no supplemental fuel will be supplied. Thus,with the switch open. the engine may be cranked to efiect deflooding,large quantities 'of air being drawn into the cylinders due to therelatively wide opening of the throttle.

While the foregoing arrangement has been shown and described inconnection with a partic ular type of fuel system it is to be understoodthat said invention may also be used in connec-- tion with many othertypes of pressure fuel systems for supplying an auxiliary orsupplemental fuel to the engine for starting and warming up of same. Forexample, in a fuel system having a fioat type of carburetor theauxiliary fuel is supplied by the pump and delivered to the inductionpassage under the control of the primer. In using the primer arrangementof the present invention it is unnecessary for the carburetor to havea'choke valve with its controls which are manual or automatic inoperation.

It is thought that the invention and many of its attendant advantageswill ;be understood from the foregoing description and it will beapparent that various changes may be made in the form,

- construction and arrangement of the parts with-.

out departing from the spirit and scope of the invention or sacrificingall of its material advantages, the form hereinabove described beingmerely a preferred embodiment.

We claim: 1..In an auxiliary fuel system for an internal combustionengine having-an ignition system: a source of fuel under pressure; aconduit-connecting said source with the engine; a valve for controllingsaid conduit; electrical means for controlling said valve: and a circuitconnecting the electrical means with a circuit of the. ignition systemwhereby the operation of said-valve is controlled in accordance with thespeed of the engine.

.. 2. The-invention defined by claim 1 wherein the first mentionedcircuit is connected with a .primary circuit of the ignition system.

3. The invention defined by claim 1 wherein the ignition system includesa switch and the first'mentioned circuit is controlled by theignition-switch.

- 4. The invention defined by claim 1- wherein 'the ignition systemincludes a distributor having 25 vacuum.

5. The invention, defined by claim 1 wherein the ignition systemincludes a distributor having a earn: a. breaker arm operated by the camfor making and breaking the primary circuit; the first mentioned circuitbeing connected to the ignition circuit in such a way that every timethe breaker arm moves to a position to complete the ignition circuit anelectrical impulse is supplied to the electrical means; and a thermostatlocated 10 in a position whereat it is responsive to engine heat forcontrolling said first mentioned circuit.

6. The --invention defined by claim 1 wherein there is an inductionpassage controlled by a throttle; and a switch for the first mentionedcir- 5 cult controlled in accordance with throttle position, saidjswitchbeing opened upon opening of the valve beyond a predetermined position.

7. The invention defined by claim 1 wherein there is a temperatureresponsive device variably 2o limiting movement of the valve.

8. The. invention defined by claim 1 wherein there is a second valve forregulating the flow of auxiliary fuel; and means for controlling saidsecond valve in accordance with manifold 9. In a fuel system for aninternal combustion engine having an ignition system: means forsupplying fuel to the engine under superatmospheric pressure; anauxiliary fuel supply conduit receiving fuel from said means and adaptedto deliver auxiliary fuel to the engine; means including a valve, forcontrolling the supply of auxiliary fuel; an electric coil for.operating said valve; and an electric circuit so connecting the coilwith the ignition system that the coil will be energized with afrequency depending upon engine speed.

10. The invention defined by claim 9 wherein the ignition .systemincludes a primary circuit to .40 which the coil is connected.

' .11. The invention defined by claim 9 wherein the, ignition systemincludes a distributor having, a circuit; a contact lever for making andbreaking the distributor circuit and a cam for as operating said lever;and the connection for the coil is with the distributor circuit wherebyan electrical .impulse is transmitted to the'coii upon each making ofthe distributor circuit.

12. The invention defined by claim 9 wherein there is a temperatureresponsive switch controlling the coil.

. -13. The invention definedby claim 9 wherein the degreeoi' movement ofthe valve is con- -trolled by a temperature responsive device.

as -l4.- The invention defined by claim 9 wherein the supply ofauxiliaryfuel is also regulated by a.-second valve; and there is means responsiveto engine charging pressure for controlling said second valve.

so 15. The-invention defined by claim 9 wherein there is a temperatureresponsive device for controlling the valve; and there is vacuumoperated means for regulating the quantity of auxiliary fuel suppliedtothe engine.

as 18. In an internal combustion engine: means for supplying fuel forthe fuel mixture at a sub-- stantially constant superatmosphericpressure; a return conduit for conveying a limited quantity of fuel tosaid: means: an ignition system; a con-"' 7 .duit for conveying thereturn fuel to the engine the electrical means with the ignition system.

17. In an internal combustion engine havin an ignition system includinga distributor in the primary circuit, said distributor including a con-.tact lever controlled by a cam whereby the primary circuit is made andbroken: a main fuel supply system; an auxiliary fuel supply system; aprimer controlling the auxiliary system; a valve for said primer; asolenoid for actuating said valve; and an electric circuit connectingthe solenoid with said distributor for intermittently energizing saidsolenoid while said primer is in operation.

18. The invention defined by claim 1'7 wherein there is temperatureresponsive means for controlling the solenoid circuit.

19. The invention defined by claim 17 wherein the engine includes athrottle for controlling the fuel mixture supplied thereto and there isa switch in the solenoid circuit adapted to be controlled in accordancewith throttle position.

20. The invention defined by claim 1'7 wherein there is a thermostatcontrolling the primer valve.

21. The invention defined by claim 17 wherein the supply of auxiliaryfuel is also regulated by engine charging pressure.

22. In a fuel system for an internal combustion engine having anignition system including a primary circuit and a distributor thereforhaving a circuit breaking device controlled bya cam: a source of fuel; apump for supplying fuel to the engine at a substantially constantpredetermined superatmospheric pressure; a return line connected withsaid pump for returning at least a limited quantity of fuel back to thesource: a primer, including a conduit. interposed in the return line andadapted to divert fuel flowing therethrough to a point for enriching theengine fuel mixture, said primer having a-valve which alternately closesthe return line and opens the conduit; and a solenoid connected with.the primary. circuit of the ignition system and adapted I to actuatesaid valve.

23. The invention defined by claim 22 including means for regulating theflow of fuel through 10 i the conduit. and means for controlling theregulating means in accordance with suction.

24. The invention defined by claim 22 includ-' ing a thermostat adaptedto urge the valve in the closing direction upon an increase in enginetemperature.

25. The invention defined by claim 22 including temperature responsivemeans for controlling said valve; and means responsive to enginecharging pressure for regulating the flow-of fuel through the-conduit.

26. In a priming devicefor supplying fuel to an internal combustionengine: an inlet and first and second outlets: a valve for controllingthe outlets; yielding means urging the valve to -a position whereatoneof the outlets is closed;

and electrical means for urging the valve to a position whereat theotheroutlet is closed.

27. The invention defined by claim 26 wherein there is means forintermittently energizing the solenoid for varying the quantity of fuelsupplied through the outlet in accordance with engine speed.

28. The invention defined by claim 26 wherein there is means adapted tobe responsive to engine charging pressure for regulating the fuel flowthrough said other outlet.

29. The invention defined by claim 26 wherein there is means forintermittently energizing the electrical means whereby the number oftimes said means is energized will increase with en-' gine speed; andmeans for regulating the flow of fuel through the other outlet inaccordance with manifold vacuum. i

' EMIL O. .WIRTH.

WILLIAM. E. LEIBING.

REFERENCES CITED The following references are of record in the file ofthis patent:

